C. ASSESSMENT CORE A. OBJECTIVE The Assessment Core is responsible for recruiting, assessing and maintaining the cohort of individuals with Autism Spectrum Disorders (ASD is defined in the UIC ACE as DSM-IV Autistic Disorder, Asperger's disorder, or Pervasive Developmental Disorder not otherwise specified) who will participate in the UIC ACE Projects l-lll. The coordination of participant recruitment, assessment tracking, and subject retention is vital for the success of UIC ACE, since all three human projects will draw their participants from the commonly established cohort developed by the Assessment Core. The Assessment Core is a team of experienced research clinicians who will use a variety of resources to recruit 1,000 individuals (children, adolescents, and adults) to be screened for ASD and then evaluated to form an appropriate sub-sample for further assessment, consent procedures, and assignment to the relevant studies being conducted by the UIC ACE. This effort will involve recruitment of a large number of families for a two-stage screening process. Families will participate in a comprehensive, state-of-the-art assessment to provide appropriate samples of consenting participants for UIC ACE Projects l-lll. This will be accomplished using established clinical operations that not only have expertise in evaluation, but a long tradition of research and maintenance of reliability on clinical instruments. In addition, the Assessment Core will actively utilize existing, well-established relationships with families and community agencies/organizations to maximize both the recruitment and the retention of research participants.